Field of the Invention
This invention relates to a control device for an air turbulence massage device having a connecting piece for an air tube in communication with a turbulence matting, an external housing having a lower and an upper housing part, a blower unit, and a device which prevents backflow of water from the turbulence matting to the blower unit and electrical motor drive.
Description of the Prior Art
A similar control device is taught by German Patent DE-PS 34 30 879. A similar device is also taught by German Utility Model DE-GM 80 06 791. The device for preventing the water backflow is constructed as a backflow-preventing or check valve which is held in a closed position by a permanent magnet and forced into an open position by compressed air produced by the blower unit. After the blower unit is shut down, the check valve is automatically brought back to the closed position by permanent magnets. The check valve is integrated into the connecting piece for the air tube or into the pressure output connecting piece of the blower unit. German Utility Model DE-GM 82 30 409 shows a check vale which is basically constructed in a similar manner and can also be integrated into the air tube. In the closed position of the check valve, water flowing back can flow out from the air tube through a discharge opening.
In such known control devices, the backflow of water to the electrical motor and the blower unit is only fully prevented if the check valve operates flawlessly. This is not absolutely ensured since the valve body of such types of check valve does not always occupy an unequivocally closed position. Thus a user sitting in a bathtub is not protected from dangers of current failures, current surges, and the like.